WASHINGTON (AP) - Senate Democrats are delaying a confirmation vote on Labor Secretary nominee Thomas Perez after Republicans threatened to use a separate hearing to criticize his handling of a whistleblower case.

A vote in the Senate Health, Education, Labor and Pensions Committee that had been set for Thursday has been pushed back to May 8.

Committee Chairman Tom Harkin of Iowa says he was concerned that Republicans would use the separate hearing to attack Perez when he would not be present to defend himself. Harkin canceled the other hearing on whistleblowers, which also was set for Thursday.

Republicans have criticized Perez for declining to intervene in a whistleblower case while he was at the Justice Department. They claim the decision was based on political ideology and not the merits of the case.